This invention relates generally to tissue localizing devices and methods for their deployment and excision. More particularly, this invention relates to an improved tissue localizing device having the ability to fixedly yet removably bound a tissue volume containing a region of interest, such as a nonpalpable lesion, foreign object, or tumor, without penetrating that tissue volume. This invention also more particularly relates to methods for deploying that device and removing it with an enclosed and intact tissue volume.
Despite the advances made in technologies such as medical imaging to assist the physician in early stage diagnosis and treatment of patients with possible atypical tissue such as cancer, it is still often necessary to sample difficult-to-reliably-reach organ or tissue lesions by biopsy to confirm the presence or absence of abnormalities or disease.
One disease for which biopsy is a critical tool is breast cancer. This affliction is responsible for 18% of all cancer deaths in women and is the leading cause of death among women aged 40 to 55.
In the detection and treatment of breast cancer, there are two general classes of biopsy: the minimally invasive percutaneous biopsy and the more invasive surgical, or xe2x80x9copenxe2x80x9d, biopsy.
Percutaneous biopsies include the use of fine needles or larger diameter core needles. They may be used on palpable lesions or under stereotactic x-ray, ultrasonic, or other guidance techniques for nonpalpable lesions and microcalcifications (which are often precursors to metastatic cell growth). In the fine needle biopsy, a physician inserts a small needle directly into the lesion and obtains a few cells with a syringe. Not only does this technique requires multiple samples, but each sample is difficult for the cytologist to analyze as the specimen cells are isolated outside the context of healthy surrounding tissue.
Larger samples may be removed via a core biopsy. This class of procedures is typically performed under stereotactic x-ray guidance in which a needle is inserted into the tissue to drill a core that is removed via vacuum aspiration, etc. Typically four to five samples are taken from the body. Examples of such stereotactic biopsy methods include the MAMMOTOME vacuum aspiration system by Johnson and Johnson of New Brunswick, N.J., the ABBI system by United States Surgical Corporation, Norwalk, Conn., and the SITESELECT system by Imagyn, Inc. of Irvine, Calif.
Open biopsies are advisable when suspicious lumps should be removed in their entirety or when core needle biopsies do not render sufficient information about the nature of the lesion. One such type of open biopsy is the wire localization biopsy.
After multiple mammograms are taken of the breast, the images are analyzed by a computer to determine the location of the suspect lesion in three dimensions. Next, after a local anesthetic is administered, a radiologist inserts a small needle into the breast and passes the needle through the suspect tissue. The radiologist then passes a wire with a hook on its end through the needle and positions the hook so that the end of the wire is distal to the suspect tissue. A final image is taken of the lesion with the accompanying wire in place, and the radiologist marks the film with a grease pencil to indicate the x-ray indicators of a suspicious lesion that should be removed. The wire is left in the tissue and the patient is taken to the operating room, sometimes hours later, where the suspect tissue is removed by a surgeon. The sample is sent to a radiologist to determine, via an x-ray examination, if the sample contains the indicators such as microcalcifications and if the sample size and border are adequate to confirm the removal of all suspicious tissue.
Examples of such wire markers are well known in the art. See, e.g., the following patents, each of which is incorporated herein by reference: U.S. Pat. No. 5,158,084 to Ghiatas, U.S. Pat. No. 5,409,004 to Sloan, U.S. Pat. No. 5,059,197 to Urie et al., U.S. Pat. No. 5,197,482 to Rank, U.S. Pat. No. 5,221,269 to Miller et al., and U.S. Pat. No. 4,592,356 to Gutierrez. Other devices such as that described in U.S. Pat. No. 5,989,265 to Bouquet De La Joliniere et al. and U.S. Pat. No. 5,709,697 to Ratcliff et al., each incorporated herein by reference, are directed to similar devices.
Despite the advantages of wire localization techniques to locate the suspect tissue for the surgeon, they have a number of severe limitations.
Such wires are often inaccurately placed and they cannot be removed except by surgical excision. For these reasons, the radiologist must mark the x-ray film or prepare notations providing instructions to the surgeon on how to find the lesion as a backup to confirm the proper location of the needle.
Because the distal tip of the wire might have been placed anywhere from the very center of the lesion to quite some distance away from the lesion, the surgeon must guide a scalpel along the wire and rely upon the skill of the radiologist and the marked x-ray film in the excision procedure. Even if the wire has been properly placed in the lesion and the x-ray film clearly shows the lesion boundary or margin, the surgeon often cannot see the tip of the wire (given the surrounding tissue) so she must remove a larger portion of tissue than is necessary to ensure proper excision.
If the lesion is not found at the end of the wire, the surgeon ends up cutting or removing non-afflicted tissue without removing the lesion. Also, if the tip of the wire penetrates the lesion, the surgeon may sever the lesion in cutting through the tissue along the wire to reach its end. In the latter case, a re-excision may be necessary to remove the entire lesion. Over twenty-five percent of wire localization procedures require re-excision. Post-excision re-imaging is almost always performed prior to closing the surgical field to ensure that the targeted tissue volume containing the suspect lesion is removed.
When marking lesions in the breast, two paddles are typically used to compress and stabilize the breast for placement of the wire. Upon release of the breast from compression, the wire marker can dislodge or migrate to another position away from the suspect tissue. It may also migrate while the patient awaits surgery. In addition, the fact that the breast is in an uncompressed state for the excision procedure renders a different view of the lesion with respect to the healthy tissue.
Various tissue localization systems have been developed to minimize inadvertent migration of the wire by configuring the wire with a bend or hook, such as Ghiatas et al., discussed above, U.S. Pat. No. 5,011,473 to Gattuma, and the MAMMALOK needle/wire localizer sold by Mitek Surgical Products, Inc., Dedham, Mass. Even if a wire does not migrate after placement, the surgeon cannot determine the shortest path to the lesion; rather, the surgeon must always follow the wire, which is rarely the more cosmetically desirable path to the lesion (such as a circumareolar approach).
Because the distal tip of the wire is often placed in the center of the suspect tissue, a problem known as xe2x80x9ctrack seedingxe2x80x9d can occur in which possible cancerous or precancerous cells are disturbed by the wire and are distributed to unaffected tissue during the procedure.
Aside from the above concerns, the use of a localization wire marker presents logistical problems. After placement, the wire protrudes from the body. It is almost always necessary for the patient to proceed with the surgical removal of the lesion immediately after wire placement to minimize the chance of infection, wire breakage or disturbance, etc. However, delays between placement of the wire and eventual excision often can exceed several hours.
What is needed is a tissue locating device that may be accurately yet removably placed into a region of tissue to surround a volume of tissue that contains a suspect region, preferably without penetrating that volume to disturb it. Such a device should reliably define the border of the volume of tissue to be removed without the risk of self- or inadvertent migration. The device should also provide a surface against which the surgeon may reliably cut when excising the tissue. Furthermore, a need remains to improve the interaction between the radiologist and surgeon, eliminate the need for post-excision x-rays and re-excision, reduce the overall time for the procedure, and allow a surgeon to select the shortest or most cosmetically desirable path to the suspect tissue.
This invention is a tissue localizing device, system, and method for its use.
The tissue localizing device includes a locator element adapted to penetrate tissue so that at least a portion of the locator element defines a tissue border along a first path. This path may include the distalmost portion of the tissue volume. This border in turn defines a volume of tissue for subsequent excision and contains a target region that may be a lesion, foreign object, one or more microcalcifications, or a palpable or nonpalpable mass. This tissue volume is substantially bounded but preferably not penetrated by the locator element. The path the locator element is adapted to follow preferably forms a loop in the tissue having a diameter of at least one centimeter. When deployed, manipulation of a proximal portion of the locator element results in a corresponding direct or proportional manipulation of the tissue volume it bounds.
Preferably the locator element is a partially radiopaque ribbon with one or more optional cutting surfaces. The locator element also preferably exhibits shape memory characteristics. Alternatively, the locator element may be plastically deformed to take an arcuate or curvilinear shape during deployment through a die.
A shoulder portion may be included in the locator element defining a boundary between a preferably more flexible, less rigid proximal portion having a smaller cross-sectional area and a stiffer, more rigid distal portion having a larger cross sectional area compared to that of the proximal portion.
This device may contain a second locator element adapted to penetrate tissue so that at least a portion of it further defines the tissue border along a second path. Again, the target region is substantially bounded but preferably not penetrated by the second locator element. Each of the first and second locator elements may be deployed through a deployment tube having a lumen in which the locator elements are slideably disposed and a distal end through which they may exit into the tissue. The second locator element may be adapted to deploy into the tissue so that it defines a second plane that is not parallel to a first plane defined by the first locator element. These planes may be angularly displaced about a common axis about ninety or forty-five degrees with respect to one another.
The locator elements are adapted to be substantially aligned when deployed with a central axis of the tissue volume they bound or with a tangential axis of that volume.
An optional suture, flexible wire, or cable may be affixed to a proximal end of the locator element to extend through the tissue volume and outside the skin surface when deployed in the body.
This invention is also a tissue localization system which includes a tissue cutting element positionable within a lumen of a driver tube, a trocar positionable within the driver tube lumen, a locator element deployment tube positionable within the driver tube lumen, and at least one locator element positionable within the deployment tube. The cutting element may additionally comprise at least one lumen or tubular member having a distal end disposed along its length.
The locator element is adapted to penetrate tissue so that at least a portion of the locator element defines a tissue border along a first path. The tissue border defines a volume of tissue for subsequent excision along the border, and contains a target region that is substantially bounded by the locator element.
An orientation element also may be attached to the locator element deployment tube, which may be rotatable in fixed angular increments and/or may be infinitely rotatably variable.
A source of energy, such as electrical (RF, etc.), thermal, acoustic, mechanical, or other may be connected to the locator element. The locator element may also be at least partially electrically insulated by a coating of insulative material on one or more sides of the element. This insulative material may have a low coefficient of friction for ease of entry into the tissue if desired.
The locator element deployment tube may comprise a distal end having a locator element cold forming die that may be adapted to plastically deform the locator element into an arcuate shape. The die may include a reverse curve and a positive curve for shaping the locator element, and it may also comprise an axially adjustable upper portion connected to a lower portion.
This invention is also a method for fixedly placing a removable locator element in tissue. This method is accomplished by penetrating through tissue at a first site to create a port or a pathway for accessing a targeted tissue volume to be excised, inserting a deployment tube containing a locator element slideably contained within a lumen of the tube through the port to a position adjacent the targeted tissue volume, and advancing a locator element through a distal end of the tube and penetrating tissue so that at least a portion of the locator element defines a tissue border along a first path. The tissue border will define a volume of tissue for subsequent excision along the tissue border. The tissue volume will contain a target region that is substantially bounded but not penetrated by the locator element.
Alternatively, the invention is a method for excising a volume of tissue which comprises advancing a locator element through tissue to define a tissue border of the volume of tissue to be excised, and cutting tissue substantially along a surface of the locator element opposite a surface of the locator element disposed immediately adjacent the tissue volume.
The locator element may be proximally withdrawn from the tissue after it is advanced to define the tissue border for eventual re-advancement through the distal end of the deployment tube or complete removal from the body.
The locator element may be placed under x-ray guidance, stereotactic x-ray guidance, ultrasonic guidance, magnetic resonance imaging guidance, and the like.
A second and even third or more locator element may also be advanced through the distal end of the deployment tube to penetrate tissue so that at least a portion thereof further defines the tissue border along a second and even third path. The second path and the third path may be non-parallel to the first path occupied by the first locator element, and may be angularly displaced with respect thereto approximately thirty degrees, forty-five degrees, ninety degrees, or at any other angle or angles the radiologist so desires.
This method also includes the step of excising the tissue volume defined by the one or more locator elements. This may be accomplished by surgically accessing the locator element and cutting tissue substantially along a surface of the locator element opposite a surface of the locator element disposed immediately adjacent the tissue volume. Preferably, the device is palpable when in position around the tissue volume. Tissue may be penetrated through any accession path to the tissue volume as the surgeon sees fit. For instance, the surgeon may cut down along the locator element deployment tube, or, when the device is disposed in breast tissue, circumareolarly.
Furthermore, excision may be accomplished or complimented by at least partially energizing the locator element with electrical energy such as RF energy, mechanical energy, thermal energy, vibrational or acoustic energy, and the like. Rotation of the locator element or elements through an angular displacement to facilitate cutting through tissue to remove the tissue volume is contemplated.